MAXIM MAX1495CCJ

19-3053; Rev 0; 10/03
KIT
ATION
EVALU
LE
B
A
IL
A
AV
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
Features
♦ High Resolution
MAX1495: 4.5 Digits (±19,999 Count)
MAX1493: 4.5 Digits (±19,999 Count)
MAX1491: 3.5 Digits (±1999 Count)
The MAX1491/MAX1493/MAX1495 do not require external-precision integrating or auto-zero capacitors, crystal oscillators, charge pumps or other circuitry required
with dual slope ADCs (commonly used in panel meter
circuits). These devices also feature on-chip buffers for
the differential signal and reference inputs, allowing
direct interface with high-impedance signal sources. In
addition, the MAX1491/MAX1493/MAX1495 use continuous internal offset calibration, and offer >100dB rejection of 50Hz and 60Hz line noise. The MAX1493/
MAX1495 perform enhanced offset calibration at
power-up. The MAX1495 also performs enhanced calibration on demand. Other features include data hold
and peak hold, and a user programmable low-battery
monitor.
♦ Selectable Voltage Reference: Internal 2.048V or
External
♦ Operate from a Single 2.7V or 5.25V Supply
♦ Selectable Input Range of ±200mV or ±2V
♦ Internal High-Accuracy Oscillator Needs No
External Components
♦ Automatic Offset Calibration
♦ Low Power: Maximum 980µA Operating Current
♦ Small 32-Pin 7mm ✕ 7mm TQFP Package (4.5
Digits), 28-Pin SSOP Package (3.5 Digits), and 28Pin DIP Package (3.5 Digits)
♦ Triplexed LCD Driver
♦ Evaluation Kit Available (Order MAX1494EVKIT)
RESOLUTION
(DIGITS)
MAX1491CAI*
0°C to +70°C 28 SSOP
MAX1491CNI
0°C to +70°C 28 DIP
3.5
MAX1493CCJ
0°C to +70°C 32 TQFP
4.5
MAX1495CCJ*
0°C to +70°C 32 TQFP
4.5
*Future product—contact factory for availability.
3.5
VNEG
DPON
BP1
BP2
BP3
26
25
AVDD
1
24 SEG13
AIN+
2
23 SEG12
AIN-
3
22 SEG11
21 SEG10
REF-
4
REF+
5
LOWBATT
6
19 SEG8
RANGE
7
18 SEG7
DPSET1
8
17 SEG6
MAX1493
MAX1495
20 SEG9
9
10
11
12
13
14
15
16
SEG5
PINPACKAGE
27
SEG4
PART
TEMP
RANGE
28
SEG3
Ordering Information
29
SEG2
Digital Multimeters
30
SEG1
Digital Voltmeters
31
HOLD
Hand-Held Meters
32
PEAK
Digital Panel Meters
INTREF
Applications
DVDD
TOP VIEW
GND
Pin Configurations
DPSET2
The MAX1493/MAX1495 come in a 32-pin 7mm ✕ 7mm
TQFP package, and the MAX1491 comes in 28-pin
SSOP and 28-pin DIP packages. All devices in this family operate over the 0°C to +70°C commercial temperature range.
♦ Sigma-Delta ADC Architecture
No Integrating Capacitors Required
No Autozeroing Capacitors Required
>100dB of Simultaneous 50Hz and 60Hz Rejection
TQFP
Pin Configurations continued at end of data sheet.
________________________________________________________________ Maxim Integrated Products
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
1
MAX1491/MAX1493/MAX1495
General Description
The MAX1491/MAX1493/MAX1495 low-power, 3.5- and
4.5-digit, analog-to-digital converters (ADCs) with integrated liquid crystal display (LCD) drivers operate from a
single 2.7V to 5.25V power supply. They include an internal reference, a high-accuracy on-chip oscillator, and a
triplexed LCD driver. An internal charge pump generates
the negative supply needed to power the integrated input
buffer for single supply operation. The ADC is configurable for either a ±2V or ±200mV input range and it outputs its conversion results to an LCD. The MAX1491 is a
3.5-digit (±1,999 count) device, and the MAX1493/
MAX1495 are 4.5-digit (±19,999 count) devices.
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
ABSOLUTE MAXIMUM RATINGS
AVDD to GND............................................................-0.3V to +6V
DVDD to GND ...........................................................-0.3V to +6V
AIN+, AIN- to GND...............................VNEG to + (AVDD + 0.3V)
REF+, REF- to GND..............................VNEG to + (AVDD + 0.3V)
LOWBATT to GND ...................................-0.3V to (AVDD + 0.3V)
INTREF, RANGE, DPSET1, DPSET2, PEAK,
HOLD to GND ......................................-0.3V to (DVDD + 0.3V)
DPON to GND..........................................-0.3V to (DVDD + 0.3V)
VNEG to GND ...........................................-2.6V to (AVDD + 0.3V)
Maximum Current into Any Pin ...........................................50mA
Continuous Power Dissipation (TA = +70°C)
32-Pin TQFP (derate 20.7mW/°C above +70°C).....1652.9mW
28-Pin SSOP (derate 9.5mW/°C above +70°C) ...........762mW
28-Pin DIP (derate 14.3mW/°C above +70°C) ........1142.9mW
Operating Temperature Range...............................0°C to +70°C
Junction Temperature ......................................................+150°C
Storage Temperature Range .............................-60°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(AVDD = DVDD = +2.7V to +5.25V, GND = 0, VREF+ - VREF- = 2.048V (external reference), CNEG= 0.1µF. All specifications are TMIN
to TMAX, unless otherwise noted. Typical values are at +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
DC ACCURACY
MAX1493/MAX1495
Noise-Free Resolution
Integral Nonlinearity (Note 1)
MAX1491
INL
-19,999
+19,999
-1999
+1999
2.000V range
±1
200mV range
±1
Count
Count
Range Change Accuracy
(VAIN+ - VAIN- = 0.100V) on 200mV range /
(VAIN+ - VAIN- = 0.100V) on 2.0V range
10:1
Ratio
Rollover Error
VAIN+ - VAIN- = full scale,
VAIN- - VAIN+ = full scale
±1.0
Count
Output Noise
Offset Error (Zero Input Reading)
10
Offset
VIN = 0 (Note 2)
Gain Error
(Note 3)
Offset Drift (Zero Reading Drift)
VIN = 0
µVP-P
-0
+0
Reading
-0.5
+0.5
%FSR
Gain Drift
0.1
µV/°C
±1
ppm/°C
5
Hz
INPUT CONVERSION RATE
Conversion Rate
ANALOG INPUTS (AIN+, AIN-) (bypass to GND with 0.1µF or greater capacitors)
Differential (Note 4)
AIN Input Voltage Range
RANGE = GND
RANGE = DVDD
Absolute GND referenced
Normal Mode 50Hz and 60Hz
Rejection (Simultaneously)
-2.0
+2.0
-0.2
+0.2
-2.2V
+2.2V
V
50Hz and 60Hz ±2%
100
dB
Common-Mode 50Hz and 60Hz
Rejection (Simultaneously)
CMR
For 50Hz ±2% and 60Hz ±2%,
RSOURCE < 10kΩ
150
dB
Common-Mode Rejection
CMR
At DC
100
dB
TA = +25°C
10
nA
10
pF
Input Leakage Current
Input Capacitance
Dynamic Input Current
2
(Note 5)
-20
_______________________________________________________________________________________
+20
nA
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
(AVDD = DVDD = +2.7V to +5.25V, GND = 0, VREF+ - VREF- = 2.048V (external reference), CNEG= 0.1µF. All specifications are TMIN
to TMAX, unless otherwise noted. Typical values are at +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
LOW-BATTERY VOLTAGE MONITOR (LOWBATT)
LOWBATT Trip Threshold
2.048
V
LOWBATT Leakage Current
10
pA
Hysteresis
20
mV
INTERNAL REFERENCE (REF- = GND, INTREF = DVDD, bypass REF+ to GND with 4.7µF capacitors)
REF Output Voltage
VREF
REF Output Short-Circuit Current
REF Output Temperature
Coefficient
TCVREF
Load Regulation
AVDD = 5V, TA = +25°C
2.007
2.089
V
TA = +25°C
1
mA
AVDD = 5V
40
ppm/°C
ISOURCE = 0µA to 300µA,
ISINK = 0µA to 30µA, TA = +25°C (Note 6)
6
mV/µA
50
µV/V
Line Regulation
Noise Voltage
2.048
0.1Hz to 10Hz
25
10Hz to 10kHz
400
µVp-p
EXTERNAL REFERENCE (INTREF = GND, bypass REF+ and REF- to GND with 0.1µF or greater capacitors)
Differential (VREF+ - VREF-)
REF Input Voltage
Absolute GND referenced
Normal-Mode 50Hz and 60Hz
Rejection (Simultaneously)
2.048
-2.2
+2.2
V
50Hz and 60Hz ±2%
100
dB
Common-Mode 50Hz and 60Hz
Rejection (Simultaneously)
CMR
For 50Hz ±2% and 60Hz ±2%,
RSOURCE < 10kΩ
150
dB
Common-Mode Rejection
CMR
At DC
100
dB
TA = +25°C
10
nA
Input Leakage Current
Input Capacitance
10
Dynamic Input Current
(Note 5)
-20
pF
+20
nA
-2.3
V
+10
µA
0.3 x
DVDD
V
CHARGE PUMP
Output Voltage
VNEG
-2.6
-2.42
DIGITAL INPUTS (INTREF, RANGE, PEAK, HOLD, DPSET1, DPSET2, DPON)
Input Current
IIN
Input Low Voltage
VINL
Input High Voltage
VINH
Input Hysteresis
VHYS
VIN = 0 or DVDD
-10
0.7 x
DVDD
DVDD = 3.0V
V
200
mV
_______________________________________________________________________________________
3
MAX1491/MAX1493/MAX1495
ELECTRICAL CHARACTERISTICS (continued)
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
ELECTRICAL CHARACTERISTICS (continued)
(AVDD = DVDD = +2.7V to +5.25V, GND = 0, VREF+ - VREF- = 2.048V (external reference), CNEG= 0.1µF. All specifications are TMIN
to TMAX, unless otherwise noted. Typical values are at +25°C, unless otherwise noted.)
PARAMETER
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
V
POWER SUPPLY
AVDD Voltage
AVDD
2.70
5.25
DVDD Voltage
DVDD
2.70
5.25
Power-Supply Rejection AVDD
PSRRA
(Note 7)
80
Power-Supply Rejection DVDD
PSRRD
(Note 7)
100
AVDD Current
IAVDD
(Note 8)
660
DVDD = 5V
320
DVDD = 3.3V
180
DVDD Current
IDVDD
V
dB
dB
µA
µA
LCD DRIVER
RMS Segment-On Voltage
1.92 x
DVDD
V
RMS Segment-Off Voltage
1/3x
DVDD
V
Display Multiplex Rate
107
Hz
LCD Data-Update Rate
2.5
Hz
Note 1: Integral nonlinearity is the derivation of the analog values at any code from its theoretical value after nulling the gain error
and offset error.
Note 2: Offset calibrated.
Note 3: Offset nulled.
Note 4: The input voltage range for the analog inputs is given with respect to the voltage on the negative input of the differential pair.
Note 5: For the range of VAIN+ or VAIN- = -2.2V to +2.2V and VREF+ or VREF- = -2.2V to +2.2V.
Note 6: External load must be constant during conversion for specified accuracy. Guaranteed specification of 2mV/mA is a result of
production test limitations.
Note 7: Measured at DC by changing the power-supply voltage from 2.7V to 5.25V and measuring its effect on the conversion error.
PSRR at 50Hz and 60Hz exceeds 120dB with filter notches of 10, 20, 30, 40, 50, or 60 Hz.
Note 8: Analog power-supply currents are measured with all digital inputs at either GND or DVDD. Digital power-supply currents
measured with all digital inputs at either GND or DVDD.
4
_______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
0
-0.5
0
-0.5
-10,000
0
10,000
MAX1491/3/5 toc03
10
0
-10,000
0
10,000
-0.2 -0.1 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
20,000
NOISE (COUNTS)
SUPPLY CURRENT
vs. SUPPLY VOLTAGE
MAX1493/MAX1495
GAIN ERROR vs. SUPPLY VOLTAGE
MAX1493/MAX1495
GAIN ERROR vs. TEMPERATURE
300
DIGITAL SUPPLY
0.04
0.02
0
-0.02
-0.04
-0.06
100
-0.08
0
-0.10
3.25
3.75
4.25
SUPPLY VOLTAGE (V)
4.75
5.25
0
MAX1491/3/5 toc06
0.06
-0.01
GAIN ERROR (% FULL SCALE)
400
0.08
MAX1491/3/5 toc05
MAX1491/3/5 toc04
ANALOG SUPPLY
2.75
15
DISPLAY COUNT
600
200
20
DISPLAY COUNT
700
500
NOISE DISTRIBUTION
25
5
-1.0
-20,000
20,000
GAIN ERROR (% FULL SCALE)
-1.0
-20,000
SUPPLY CURRENT (µA)
MAX1491/3/5 toc02
0.5
INL (COUNTS)
0.5
INL (COUNTS)
1.0
MAX1491/3/5 toc01
1.0
MAX1493/MAX1495 (±2V INPUT RANGE)
INL vs. DISPLAY COUNT
PERCENTAGE OF UNITS (%)
MAX1493/MAX1495 (±200mV INPUT RANGE)
INL vs. DISPLAY COUNT
-0.02
-0.03
-0.04
-0.05
-0.06
-0.07
-0.08
-0.09
-0.10
2.75
3.25
3.75
4.25
SUPPLY VOLTAGE (V)
4.75
5.25
0
10
20
30
40
50
60
70
TEMPERATURE (°C)
_______________________________________________________________________________________
5
MAX1491/MAX1493/MAX1495
Typical Operating Characteristics
(AVDD = DVDD = 5V, GND = 0, REF+ = 2.048V, REF- = GND, RANGE = DVDD, TA = +25°C.)
Typical Operating Characteristics (continued)
(AVDD = DVDD = 5V, GND = 0, REF+ = 2.048V, REF- = GND, RANGE = DVDD, TA = +25°C.)
2.050
2.049
2.048
2.047
2.046
2.048
2.047
2.046
MAX1491/3/5 toc09
2.049
700
600
SUPPLY CURRENT (µA)
REFERENCE VOLTAGE (V)
2.051
MAX1491/3/5 toc08
2.053
2.052
2.050
REFERENCE VOLTAGE (V)
MAX1491/3/5 toc07
2.054
SUPPLY CURRENT
vs. TEMPERATURE
INTERNAL REFERENCE VOLTAGE
vs. ANALOG SUPPLY VOLTAGE
INTERNAL REFERENCE VOLTAGE
vs. TEMPERATURE
2.045
ANALOG SUPPLY
500
400
300
DIGITAL SUPPLY
200
100
2.045
0
2.044
2.044
10
20
30
40
50
60
2.75
70
3.25
3.75
4.25
4.75
0
5.25
10
20
30
40
50
60
TEMPERATURE (°C)
SUPPLY VOLTAGE (V)
TEMPERATURE (°C)
CHARGE-PUMP OUTPUT VOLTAGE
vs. ANALOG SUPPLY VOLTAGE
VNEG STARTUP SCOPE SHOT
OFFSET ERROR
vs. COMMON-MODE VOLTAGE
VDD
2V/div
-2.44
1V/div
VNEG
-2.46
70
MAX1491/3/5 toc12
-2.42
0.20
0.15
OFFSET ERROR (COUNTS)
MAX1491/3/5 toc10
-2.40
MAX1491/3/5 toc11
0
VNEG VOLTAGE (V)
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
0.10
0.05
0
-0.05
-0.10
-2.48
-0.15
CNEG = 0.1µF
-0.20
-2.50
2.75
3.25
3.75
4.25
SUPPLY VOLTAGE (V)
6
4.75
5.25
20ms/div
-2.0 -1.5 -1.0 -0.5
0
0.5
1.0
COMMON-MODE VOLTAGE (V)
_______________________________________________________________________________________
1.5
2.0
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
PIN
MAX1493
MAX1495
NAME
MAX1491
FUNCTION
1
30
INTREF
2
31
DVDD
3
32
GND
Ground
Internal Reference Logic Input. Connect to GND to select external reference mode. Connect
to DVDD to select the internal reference mode.
Digital Power Input. Connect DVDD to a 2.7V to 5.25V power supply. Bypass DVDD to GND
with a 0.1µF and a 4.7µF capacitor.
4
1
AVDD
Analog Power Input. Connect AVDD to a 2.7V to 5.25V power supply. Bypass AVDD to GND
with a 0.1µF and a 4.7µF capacitor.
5
2
AIN+
Positive Analog Input. Positive side of fully differential analog input. Bypass AIN+ to GND with
a 0.1µF or greater capacitor.
6
3
AIN-
Negative Analog Input. Negative side of fully differential analog input. Bypass AIN- to GND
with a 0.1µF or greater capacitor.
7
4
REF-
Negative Reference Input. For internal reference operation, connect REF- to GND. For
external reference operation, bypass REF- to GND with a 0.1µF capacitor and set VREF- from
-2.2V to +2.2V, provided VREF+ > VREF-.
8
5
REF+
Positive Reference Input. For internal reference operation, connect a 4.7µF capacitor from
REF+ to GND. For external reference operation, bypass REF+ to GND with a 0.1µF capacitor
and set VREF+ from -2.2V to +2.2V, provided VREF+ > VREF-.
9
6
10
7
RANGE
Range Logic Input. RANGE controls the fully differential analog input range. Connect to GND
for the ±2V input range. Connect to DVDD for the ±200mV input range.
11
8
DPSET1
Decimal Point Logic Input 1. Controls the decimal point of the LCD. See the Decimal Point
Control section.
12
9
DPSET2
Decimal Point Logic Input 2. Controls the decimal point of the LCD. See the Decimal Point
Control section.
13
10
PEAK
Peak Logic Input. Connect to DVDD to display the highest ADC value on the LCD. Connect to
GND to disable the peak function.
LOWBATT Low Battery Input. When VLOWBATT < 2.048V (typ), the LOWBATT symbol on the LCD turns on.
14
11
HOLD
Hold Logic Input. Connect to DVDD to hold the current ADC value on the LCD. Connect to
GND to update the LCD at a rate of 2.5Hz and disable the hold function. For the MAX1495,
placing the device into hold mode initiates an enhanced offset calibration. Assert HOLD high
for a minimum of 2s to ensure the completion of enhanced offset calibration.
15
12
SEG1
LCD Segment 1 Driver
16
13
SEG2
LCD Segment 2 Driver
17
14
SEG3
LCD Segment 3 Driver
18
15
SEG4
LCD Segment 4 Driver
19
16
SEG5
LCD Segment 5 Driver
20
17
SEG6
LCD Segment 6 Driver
_______________________________________________________________________________________
7
MAX1491/MAX1493/MAX1495
Pin Description
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
MAX1491/MAX1493/MAX1495
Pin Description (continued)
PIN
MAX1493
MAX1495
NAME
MAX1491
21
18
SEG7
LCD Segment 7 Driver
22
19
SEG8
LCD Segment 8 Driver
23
20
SEG9
LCD Segment 9 Driver
24
21
SEG10
LCD Segment 10 Driver
25
25
BP3
LCD Backplane 3 Driver
26
26
BP2
LCD Backplane 2 Driver
27
27
BP1
28
29
VNEG
—
22
SEG11
LCD Segment 11 Driver
—
23
SEG12
LCD Segment 12 Driver
—
24
SEG13
LCD Segment 13 Driver
—
28
DPON
Decimal Point Enable Input. Controls the decimal point of the LCD. See the Decimal Point
Control section. Connect to DVDD to enable the decimal point.
DVDD
AVDD
FUNCTION
LCD Backplane 1 Driver
-2.5V Charge-Pump Voltage Output. Connect a 0.1µF capacitor from VNEG to GND.
DPON
HOLD
MAX1493
MAX1495
DPSET1
DPSET2
RANGE
PEAK
INTREF
CONTROL
+2.5V
SEG1
BINARY-TO-BCD
CONVERTERS
AND
LCD DRIVERS
AIN+
ADC
AIN-
SEG13
BP1
BP2
BP3
INPUT
BUFFERS
REF+
OSCILLATOR/
CLOCK
REF-
-2.5V
+2.5V
-2.5V
2.048V
BANDGAP
REFERENCE
GND
A = 1.22
TO
CONTROL
CHARGE
PUMP
VNEG
LOWBATT
Figure 1. MAX1493/MAX1495 Functional Diagram
8
_______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
The MAX1491/MAX1493/MAX1495 low-power, highly
integrated ADCs with LCD drivers convert a ±2V differential input voltage (one count is equal to 100µV for the
MAX1493/MAX1495 and 1mV for the MAX1491) with a
sigma-delta ADC and output the result to an LCD. An
additional ±200mV input range (one count is equal to
10µV for the MAX1493/MAX1495 and 100µV for the
MAX1491) is available to measure small signals with
increased resolution.
Digital Filtering
The MAX1491/MAX1493/MAX1495 contain an on-chip
digital lowpass filter that processes the data stream
from the modulator using a SINC4 (sinx/x)4 response.
The SINC4 filter has a settling time of four output data
periods (4 x 200ms).
The MAX1491/MAX1493/MAX1495 have 25% overrange
capability built into the modulator and digital filter:


f 
 sin Nπ  
fm  

1
H(f) = 
N
 f  
 sin π  

 fm  
These devices operate from a single 2.7V to 5.25V power
supply and offer 3.5-digit (MAX1491) or 4.5-digit
(MAX1493/MAX1495) conversion results. An internal
2.048V reference, internal charge pump and a high-accuracy on-chip oscillator eliminate external components.
These devices also feature on-chip buffers for the differential input signal and external reference inputs,
allowing direct interface with high-impedance signal
sources. In addition, they use continuous internal offset
calibration, and offer >100dB of 50Hz and 60Hz line
noise rejection. Other features include data hold and
peak hold, and a low-battery monitor. The MAX1495
also performs enhanced offset calibration on demand.
Analog Input Protection
Internal protection diodes limit the analog input range
from V NEG to (AV DD + 0.3V). If the analog input
exceeds this range, limit the input current to 10mA.
Internal Analog Input/
Reference Buffers
The MAX1491/MAX1493/MAX1495 analog input/reference buffers allow the use of high-impedance signal
sources. The input buffers’ common-mode input range
allows the analog inputs and reference to range from
-2.2V to +2.2V.
( )
( )
 1- z -N
1
H(z) = 
-1
 N 1- z

4
Filter Characteristics
Figure 2 shows the filter frequency response. The SINC4
characteristic -3dB cutoff frequency is 0.228 times the
first notch frequency (5Hz). The oversampling ratio
(OSR) for the MAX1491 is 128 and the OSR for the
MAX1493/MAX1495 is 1024.
The output data rate for the digital filter corresponds
with the positioning of the first notch of the filter’s frequency response. The notches of the SINC4 filter are
repeated at multiples of the first notch frequency. The
SINC 4 filter provides an attenuation of better than
100dB at these notches. For example, 50Hz is equal to
10 times the first notch frequency and 60Hz is equal to
12 times the first notch frequency.
0
Modulator
-40
GAIN (dB)
The MAX1491/MAX1493/MAX1495 perform analog-todigital conversions using a single-bit, 3rd-order, sigmadelta modulator. The sigma-delta modulation converts
the input signal into a digital pulse train whose average
duty cycle represents the digitized signal information.
The modulator quantizes the input signal at a much
higher sample rate than the bandwidth of the input.
The MAX1491/MAX1493/MAX1495 modulator provides
3rd-order frequency shaping of the quantization noise
resulting from the single-bit quantizer. The modulator is
fully differential for maximum signal-to-noise ratio and
minimum susceptibility to power-supply noise. A singlebit data stream is then presented to the digital filter for
processing, to remove the frequency-shaped quantization noise.





4
-80
-120
-160
-200
0
10
20
30
40
50
60
FREQUENCY (Hz)
Figure 2. Frequency Response of the SINC4 Filter (Notch at 60Hz)
_______________________________________________________________________________________
9
MAX1491/MAX1493/MAX1495
Detailed Description
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
Internal Clock
The MAX1491/MAX1493/MAX1495 contain an internal
oscillator. Using the internal oscillator saves board
space by removing the need for an external clock
source. The oscillator is optimized to give 50Hz and
60Hz power supply and common-mode rejection.
Y
X
The MAX1491/MAX1493/MAX1495 contain an internal
charge pump to provide the negative supply voltage for
the internal analog input/reference buffers. The bipolar
input range of the analog input/reference buffers allows
the devices to accept negative inputs with high source
impedances. For the charge pump to operate correctly,
connect a 0.1µF capacitor from VNEG to GND.
LCD Driver
Triplexing
An internal resistor string of three equal-value resistors
(52kΩ, 1% matching) is used to generate the display
drive voltages. One end of the string is connected to
DVDD and the other end is connected to GND. Note that
VLCD (VLCD = DVDD - GND) should be three times the
threshold voltage for the liquid-crystal material used.
The connection diagram for a typical 7-segment display
font with two annunciators is illustrated in Figure 3 and
Figure 8. The MAX1491/MAX1493/MAX1495 numeric
display drivers (4.5 digits, 3.5 digits) use this configuration to drive a triplexed LCD with three backplanes and
13 segment driver lines (10 for 3.5 digits). Figures 4 and
5 show the assignment of the 4.5-digit display segments
and Figures 6 and 7 show the assignment of the 3.5digit display segments.
Table 1. List of LCD Manufacturers
MANUFACTURER
DCI, Inc.
WEBSITE
www.dciincorporated.com
LXD, Inc.
www.lxdinc.com
Varitronix International Limited
www.varitronix.com
The following site has more links to custom LCD
manufacturers: www.earthlcd.com/mfr.htm
10
a
a
Charge Pump
The MAX1491/MAX1493/MAX1495 contain the necessary backplane and segment driver outputs to drive
3.5-digit (MAX1491) and 4.5-digit (MAX1493/MAX1495)
LCDs. The LCD update rate is 2.5Hz. Figures 4–7 show
the connection schemes for a standard LCD. The
MAX1491/MAX1493/MAX1495 automatically display the
results of the ADC.
Z
f
b
f
BP1
b
g
g
e
c
e
BP2
d
d
DP
c
ANNUNCIATOR
BP3
DP
ANNUNCIATOR
Figure 3. Connection Diagrams for Typical Seven-Segment
Displays
The voltage waveforms of the backplane lines and y
segment line (Figure 3) have been chosen as an example. This line intersects with BP1 to form the a segment,
with BP2 to form the g segment, and with BP3 to form
the d segment. Eight different ON/OFF combinations of
the a, g, and d segments and their corresponding
waveforms of the y segment line are illustrated in
Figures 9 and 10. The schematic diagram in Figure 8
shows that each intersection acts as a capacitance
from segment line to common line. Figure 11 illustrates
the voltage across the g segment.
The RMS voltage across the segment determines the
degree of polarization for the liquid-crystal material and
thus the contrast of the segment. The RMS OFF voltage
is always VLCD / 3, whereas the RMS ON voltage is
always 1.92VLCD / 3. This is illustrated in Figure 11. The
ratio of RMS ON to OFF voltage is fixed at 1.92 for a
triplexed LCD.
Figure 12 illustrates contrast vs. applied RMS voltage
with a VLCD of 3.1V. The RMS ON voltage is 2.1V and
the RMS OFF voltage is 1.1V. The OFF segment has a
contrast of less than 5%, while the ON segments have
greater than 85% contrast.
If ghosting is present on the LCD, the RMS OFF voltage
is too high. Choose an LCD with a higher RMS OFF
voltage or decrease DVDD.
______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
PEAK
MAX1491/MAX1493/MAX1495
HOLD
LOW BATT
BP1
BP2
BP3
Figure 4. Backplane Connection for the MAX1493/MAX1495 (4.5 Digits)
SEG13: PEAK, HOLD, N.C.
HOLD
LOW BATT
PEAK
SEG12: F4, E4, DP4
SEG11: A4, G4, D4
SEG2: A1, G1, D1
ANNUNCIATOR
SEG1: B1, C1, ANNUNCIATOR
SEG3: F1, E1, DP1
SEG10: B4, C4, BC5
SEG4: B2, C2, LOWBATT
SEG9: F3, E3, DP3
SEG5: A2, G2, D2
SEG6: F2, E2, DP2
SEG8: A3, G3, D3
SEG7: B3, C3, MINUS
Figure 5. Segment Connection for the MAX1493/MAX1495 (4.5 Digits)
______________________________________________________________________________________
11
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
HOLD
PEAK
LOW BATT
BP1
BP2
BP3
Figure 6. Backplane Connection for the MAX1491 (3.5 Digits)
SEG10: PEAK, HOLD, BC4
HOLD
PEAK
LOW BATT
SEG2: A1, G1, D1
ANNUNCIATOR
SEG1: B1, C1, ANNUNCIATOR
SEG3: F1, E1, DP1
SEG4: B2, C2, LOWBATT
SEG9: F3, E3, DP3
SEG5: A2, G2, D2
SEG8: A3, G3, D3
SEG6: F2, E2, DP2
SEG7: B3, C3, MINUS
Figure 7. Segment Connection for the MAX1491 (3.5 Digits)
X
BP1
BP2
BP3
Y
Z
f
a
b
e
g
c
DP
d
DP
Figure 8. Schematic of Display Digit
12
______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
φ2
φ3
φ1'
φ2'
MAX1491/MAX1493/MAX1495
φ1
φ3'
V+
VH
BP1
VLCD
VL
VV+
VH
BP2
VL
VV+
VH
BP3
VL
VV+
VH
ALL
OFF
VL
VV+
VH
a ON
g, d OFF
VL
VV+
VH
g ON
a, d OFF
VL
VV+
VH
d ON
a, g OFF
VL
VFREQUENCY = 107Hz
φ1, φ2, φ3 - - BP HIGH WITH RESPECT TO SEGMENT (BP+ TIME)
φ1', φ2', φ3' - - BP LOW WITH RESPECT TO SEGMENT (BP- TIME)
BP1 ACTIVE DURING φ1 AND φ1'
BP2 ACTIVE DURING φ2 AND φ2'
BP3 ACTIVE DURING φ3 AND φ3'
V+ = DVDD, VH = 2/3 DVDD
VL = 1/3 VLCD, V- = GND
VLCD = DVDD - GND
Figure 9. LCD Voltage Waveform—Combinations 1–4 (BP1/2/3, SEGa/d/g)
______________________________________________________________________________________
13
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
φ1
φ2
φ3
φ1'
φ2'
φ3'
V+
VH
BP1
VLCD
VL
VV+
VH
BP2
VL
VV+
VH
BP3
VL
VV+
VH
ALL
OFF
VL
VV+
VH
a, d ON
g OFF
VL
VV+
VH
a, g ON
d OFF
VL
VV+
VH
g, d ON
a OFF
VL
V-
FREQUENCY = 107Hz
φ1, φ2, φ3 - - BP HIGH WITH RESPECT TO SEGMENT (BP+ TIME)
φ1', φ2', φ3' - - BP LOW WITH RESPECT TO SEGMENT (BP- TIME)
BP1 ACTIVE DURING φ1 AND φ1'
BP2 ACTIVE DURING φ2 AND φ2'
BP3 ACTIVE DURING φ3 AND φ3'
V+ = DVDD, VH = 2/3 DVDD
VL = 1/3 VLCD, V- = GND
VLCD = DVDD - GND
Figure 10. LCD Voltage Waveform—Combinations 5–8 (BP1/2/3, SEGa/d/g)
14
______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
φ2
φ3
φ1'
φ2'
MAX1491/MAX1493/MAX1495
φ1
φ3'
VLCD
ALL
OFF
0
VRMS = VLCD / 3 (OFF)
-VLCD
VLCD
a ON
g, d OFF
0
VRMS = VLCD / 3 (OFF)
-VLCD
VLCD
a, g ON
d OFF
0
VRMS = 1.92VLCD / 3 (ON)
-VLCD
VLCD
ALL
ON
0
VRMS = 1.92VLCD / 3 (ON)
-VLCD
VG = VY - VBP2 (DIFFERENCE BETWEEN SEGMENT LINE Y AND BP2 VOLTAGE)
VOLTAGE CONTRAST RATIO = VRMS ON / VRMSOFF = 1.922
φ1, φ2, φ3 - - BP HIGH WITH RESPECT TO SEGMENT (BP+ TIME)
φ1', φ2', φ3' - - BP LOW WITH RESPECT TO SEGMENT (BP- TIME)
BP1 ACTIVE DURING φ1 AND φ1'
BP2 ACTIVE DURING φ2 AND φ2'
BP3 ACTIVE DURING φ3 AND φ3'
Figure 11. Voltage Waveforms on the g Segment
______________________________________________________________________________________
15
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
100
90
Ø = -10°C
80
Ø = +10°C
CONTRAST (%)
70
Ø = -30°C
60
Ø = 0°C
50
40
30
VOFF =
1.1VRMS
20
VON = 2.1VRMS
10
TA = +25°C
0
0
1
2
3
4
5
APPLIED VOLTAGE (VRMS)
Ø+
Ø-
Figure 12. Contrast vs. Applied RMS Voltage
16
______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
with a 0.1µF or greater capacitor to GND in external reference mode.
Figure 13 shows the MAX1493/MAX1495 operating with
an external differential reference. In this mode, REF- is
connected to the top of the strain gauge and REF+ is
connected to the midpoint of the resistor-divider on the
supply.
Reference
Applications Information
The MAX1491/MAX1493/MAX1495 reference sets the
full-scale range of the ADC transfer function. With a
nominal 2.048V reference, the ADC full-scale range is
±2V with RANGE equal to GND. With RANGE equal to
DVDD, the full-scale range is ±200mV. A decreased reference voltage decreases full-scale range (see the
Transfer Functions section).
The MAX1491/MAX1493/MAX1495 accept either an
external reference or an internal reference. The INTREF
input selects the reference mode.
For internal reference operation, connect INTREF to
DV DD , connect REF- to GND, and bypass REF+ to
GND with a 4.7µF capacitor. The internal reference provides a nominal 2.048V source between REF+ and
GND. The internal reference temperature coefficient is
typically 40ppm/°C.
Connect INTREF to GND to use the external reference.
The external reference inputs, REF+ and REF-, are fully
differential. For a valid external reference input, VREF+
must be greater than VREF-. Bypass REF+ and REF-
Power-On
At power-on, the digital filter and modulator circuits
reset. The MAX1493/MAX1495 allow 6s for the reference to stabilize before performing enhanced offset
calibration. During these 6s, the MAX1493/MAX1495
display 1.2V to 1.5V when a stable reference is detected. If a valid reference is not found, the MAX1493/
MAX1495 time out after 6s and begin enhanced offset
calibration. Enhanced offset calibration typically lasts
2s. The MAX1493/MAX1495 begin converting after
enhanced offset calibration.
Offset Calibration
The MAX1491/MAX1493/MAX1495 offer on-chip offset
calibration. The MAX1491/MAX1493/MAX1495 calibrate
offset during every conversion cycle. The MAX1495
offers enhanced offset calibration on demand. Connect
HOLD to DVDD for 2s to perform enhanced offset calibration.
Table 2. Decimal-Point Control Table (MAX1493/MAX1495)
DPON
DPSET1
DPSET2
DISPLAY OUTPUT
ZERO INPUT READING
0
0
0
18888
0
0
0
1
18888
0
0
1
0
18888
0
0
1
1
18888
0
1
0
0
1 8 8 8.8
0.0
1
0
1
1 8 8.8 8
0.00
1
1
0
1 8.8 8 8
0.000
1
1
1
1.8 8 8 8
0.0000
Table 3. Decimal-Point Control Table (MAX1491)
DPSET1
DPSET2
DISPLAY OUTPUT
ZERO INPUT READING
0
0
1 8 8.8
0.0
0
1
1 8.8 8
0.00
1
0
1.8 8 8
0.000
1
1
1888
000
______________________________________________________________________________________
17
MAX1491/MAX1493/MAX1495
Decimal Point Control
The MAX1491/MAX1493/MAX1495 allow for full decimal-point control and feature leading-zero suppression.
Use DPON, DPSET1, and DPSET2 to set the value of
the decimal point. Tables 2 and 3 show the truth tables
of the DPON, DPSET1, and DPSET2 that determine
which decimal point is used.
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
Peak
The MAX1491/MAX1493/MAX1495 feature peak detection circuitry. When activated (PEAK connected to DVDD),
the devices display only the highest voltage measured to
the LCD. First, the current ADC result is displayed. Then
the new ADC conversion result is compared to this value.
If the new value is larger than the previous peak value,
the new value is displayed. If the new value is less than
the previous peak value, the display remains unchanged.
Connect PEAK to GND to clear the peak value and disable the peak function. The peak function is only valid for
the -19,487 to +19,999 range for the MAX1493/
MAX1495 and -1217 to +1999 for the MAX1491.
Hold
ANALOG SUPPLY
FERRITE
BEAD
0.1µF
AVDD
DVDD
REF+
0.1µF
RREF
MAX1491
MAX1493
MAX1495
REF0.1µF
The MAX1491/MAX1493/MAX1495 feature data HOLD
circuitry. When activated (HOLD connected to DVDD),
the devices hold the current reading on the LCD.
ACTIVE
GAUGE
Low Battery
DUMMY
GAUGE
The MAX1491/MAX1493/MAX1495 feature a low-battery
detection input. When the voltage at LOWBATT drops
below 2.048V (typ), the LOWBATT segment of the LCD
turns on.
4.7µF
0.1µF
4.7µF
VNEG
0.1µF
R
AIN+
0.1µF
AIN0.1µF
R
INTREF
GND
Strain Gauge Measurement
Connect the differential inputs of the MAX1491/
MAX1493/MAX1495 to the bridge network of the strain
gauge. In Figure 13, the analog supply voltage powers
the bridge network and the MAX1491/MAX1493/
MAX1495 along with its reference voltage. The
MAX1491/MAX1493/MAX1495 handle an analog input
voltage range of ±200mV or ±2V full scale. The analog/reference inputs of the part allow the analog input
range to have an absolute value anywhere between
-2.2V and +2.2V.
Figure 13. Strain-Gauge Application with the MAX1491/MAX1493/
MAX1495
R = 100Ω for ±2V RANGE
10Ω for ±200mV RANGE
4–20mA Measurement
To measure 4–20mA signals, connect a shunt resistor
across AIN+ and AIN- to create the ±2V or ±200mV
input voltage (see Figure 14).
Table 4. LCD Priority Table
HOLD
18
AIN+
0.1µF
4–20mA
MAX1491
MAX1493
AIN- MAX1495
R
0.1µF
PEAK
DISPLAYS
DVDD
X
Current value
GND
DVDD
Peak value
GND
GND
Latest ADC result
±1.8.8.8.8
Figure 14. 4–20mA Measurement
______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
V

-V
Counts = 1.024 ×  AIN+ AIN-  × 20,000
 VREF + - VREF- 
The transfer function for the MAX1493 with AIN+ - AIN< 0 and RANGE = GND is:
V

-V
Counts = 1.024 ×  AIN+ AIN- × 20,000 + 1
 VREF + - VREF
The transfer function for the MAX1491 with AIN+ - AIN≥ 0 and RANGE = GND is:
V

-V
Counts = 1.024 ×  AIN+ AIN-  × 2000
 VREF + - VREF- 
The transfer function for the MAX1491 with AIN+ - AIN< 0 and RANGE = GND is:
V

-V
Counts = 1.024 ×  AIN+ AIN- × 2000 + 1
 VREF + - VREF
The transfer function for the MAX1493/MAX1495 with
AIN+ - AIN- ≥ 0 and RANGE = DVDD is:
V

-V
Counts = 1.024 ×  AIN+ AIN-  × 20,000 × 10
 VREF + - VREF- 
The transfer function for the MAX1493 with AIN+ - AIN< 0 and RANGE = DVDD is:
V

-V
Counts = 1.024 ×  AIN+ AIN- × 20,000 × 10 + 1
V
V
 REF + REF
The transfer function for the MAX1491 with AIN+ - AIN≥ 0 and RANGE = DVDD is:
V

-V
Counts = 1.024 ×  AIN+ AIN-  × 2000 × 10
 VREF + - VREF- 
The transfer function for the MAX1491 with AIN+ - AIN< 0 and RANGE = DVDD is:
V

-V
Counts = 1.024 ×  AIN+ AIN- × 2000 × 10 + 1
 VREF + - VREF
LCD
LCD
1----
1----
19,999
19,999
2
1
2
1
0
0
-0
-0
-1
-1
-2
-2
-19,999
-19,999
-1----
-1----2V
-100µV 0 100µV
+2V
ANALOG INPUT VOLTAGE
Figure 15. MAX1493/MAX1495 Transfer Function ±2V Range
-200mV
-10µV 0 10µV
+200mV
ANALOG INPUT VOLTAGE
Figure 16. MAX1493/MAX1495 Transfer Function ±200mV Range
______________________________________________________________________________________
19
MAX1491/MAX1493/MAX1495
Transfer Functions
Figures 15–18 show the MAX1491/MAX1493s’ transfer
functions. The transfer function for the MAX1493/
MAX1495 with AIN+ - AIN- ≥ 0 and RANGE = GND is:
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
LCD
LCD
1---
1---
1999
1999
2
1
2
1
0
0
-0
-0
-1
-1
-2
-2
-1999
-1999
-1---
-1---200mV
-100µV 0 100µV
+200mV
ANALOG INPUT VOLTAGE
Figure 17. MAX1491 Transfer Function ±200mV Range
-2V
-1mV 0 1mV
Figure 18. MAX1491 Transfer Function ±2V Range
Definitions
Supplies, Layout, and Bypassing
Power up AVDD and DVDD before applying an analog
input and external reference voltage to the device. If
this is not possible, limit the current into these inputs to
50mA. Isolate the digital supply from the analog supply
with a low-value resistor (10Ω) or ferrite bead when the
analog and digital supplies come from the same
source. For best performance, ground the MAX1491/
MAX1493/MAX1495 to the analog ground plane of the
circuit board.
Avoid running digital lines under the device, because
these may couple noise onto the die. Run the analog
ground plane under the MAX1491/MAX1493/MAX1495
to minimize coupling of digital noise. Make the powersupply lines to the MAX1491/MAX1493/MAX1495 as
wide as possible to provide low-impedance paths and
reduce the effects of glitches on the power-supply line.
Shield fast-switching signals, such as clocks, with digital
ground to avoid radiating noise to other sections of the
board. Avoid running clock signals near the analog
inputs. Avoid crossover of digital and analog signals.
Running traces that are on opposite sides of the board at
right angles to each other reduces feedthrough effects.
Good decoupling is important when using high-resolution ADCs. Decouple the supplies with 4.7µF and 0.1µF
ceramic capacitors to GND. Place these components
as close to the device as possible to achieve the
best decoupling.
INL
Integral nonlinearity (INL) is the deviation of the values
on an actual transfer function from a straight line. This
straight line is either a best-straight-line fit or a line
drawn between the end points of the transfer function,
once offset and gain errors have been nullified. INL for
the MAX1491/MAX1493/MAX1495 is measured using
the end-point method.
DNL
Differential nonlinearity (DNL) is the difference between
an actual step width and the ideal value of one count. A
DNL error specification of less than one count guarantees
no missing counts and a monotonic transfer function.
Rollover Error
Rollover error is defined as the absolute value difference between a near-positive full-scale reading and
near-negative full-scale reading. Rollover error is tested
by applying a full-scale positive voltage, swapping
AIN+ and AIN-, and then adding the results.
Zero Input Reading
Ideally, with AIN+ connected to AIN-, the MAX1491/
MAX1493/MAX1495 display a zero. Zero input reading
is the measured deviation from the ideal zero and the
actual measured point.
Refer to the MAX1494 evaluation kit manual for the recommended layout. The evaluation board package
includes a fully assembled and tested evaluation board.
20
+2V
ANALOG INPUT VOLTAGE
______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
Common-Mode Rejection
Common-mode rejection is the ability of a device to
reject a signal that is common to both input terminals.
The common-mode signal can be either an AC or a DC
signal or a combination of the two. CMR is often
expressed in decibels.
Normal-Mode 50Hz and 60Hz Rejection
(Simultaneously)
Normal mode rejection is a measure of how much output
changes when 50Hz and 60Hz signals are injected into
just one of the differential inputs. The MAX1491/
MAX1493/MAX1495 sigma-delta converter uses its internal digital filter to provide normal mode rejection to both
50Hz and 60Hz power-line frequencies simultaneously.
Power-Supply Rejection Ratio
Power-supply rejection ratio (PSRR) is the ratio of the
input supply change (in volts) to the change in the converter output (in volts). It is measured typically
in decibels.
Enhanced Offset Calibration
Enhanced offset calibration is a more accurate calibration method that is needed in the case of the ±200mV
range and 4.5-digit resolution. The MAX1493/MAX1495
perform the enhanced offset calibration upon power-up.
The MAX1495 also performs enhanced offset calibration
on demand with the HOLD input.
Typical Operating Circuit
HOLD
LOW BATTERY
SEG1–SEG13
(SEG1–SEG10)
AIN+
VIN
PEAK
BACKPLANE
CONNECTIONS
DVDD
AIN0.1µF
INTREF
0.1µF
PEAK
DVDD
4.7µF
HOLD
MAX1493
MAX1495
(MAX1491)
0.1µF
DPON
DPSET1
DPSET2
AVDD
LOWBATT
4.7µF
RHI
LISO
2.7V TO
5.25V
VNEG
GND
0.1µF
REF-
RANGE
REF+
4.7µF
10µF
RLOW
______________________________________________________________________________________
21
MAX1491/MAX1493/MAX1495
Gain Error
Gain error is the amount of deviation between the measured full-scale transition point and the ideal full-scale
transition point.
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
MAX1491/MAX1493/MAX1495
Pin Configurations (continued)
TOP VIEW
INTREF 1
28 VNEG
DVDD 2
27 BP1
GND 3
26 BP2
AVDD 4
25 BP3
AIN+ 5
AIN- 6
Chip Information
TRANSISTOR COUNT: 79,435
PROCESS: BiCMOS
24 SEG10
MAX1491
23 SEG9
REF- 7
22 SEG8
REF+ 8
21 SEG7
LOWBATT 9
20 SEG6
RANGE 10
19 SEG5
DPSET1 11
18 SEG4
DPSET2 12
17 SEG3
PEAK 13
16 SEG2
HOLD 14
15 SEG1
SSOP OR DIP
22
______________________________________________________________________________________
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
32L/48L,TQFP.EPS
______________________________________________________________________________________
23
MAX1491/MAX1493/MAX1495
Package Information
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)
2
SSOP.EPS
MAX1491/MAX1493/MAX1495
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
1
INCHES
E
H
MILLIMETERS
DIM
MIN
MAX
MIN
MAX
A
0.068
0.078
1.73
1.99
A1
0.002
0.008
0.05
0.21
B
0.010
0.015
0.25
0.38
C
0.20
0.09
0.004 0.008
SEE VARIATIONS
D
E
e
0.205
0.212
0.0256 BSC
5.20
MILLIMETERS
INCHES
D
D
D
D
D
5.38
MIN
MAX
MIN
MAX
0.239
0.239
0.278
0.249
0.249
0.289
6.07
6.07
7.07
6.33
6.33
7.33
0.317
0.397
0.328
0.407
8.07
10.07
8.33
10.33
N
14L
16L
20L
24L
28L
0.65 BSC
H
0.301
0.311
7.65
7.90
L
0.025
0∞
0.037
8∞
0.63
0∞
0.95
8∞
N
A
C
B
e
A1
L
D
NOTES:
1. D&E DO NOT INCLUDE MOLD FLASH.
2. MOLD FLASH OR PROTRUSIONS NOT TO EXCEED .15 MM (.006").
3. CONTROLLING DIMENSION: MILLIMETERS.
4. MEETS JEDEC MO150.
5. LEADS TO BE COPLANAR WITHIN 0.10 MM.
PROPRIETARY INFORMATION
TITLE:
PACKAGE OUTLINE, SSOP, 5.3 MM
APPROVAL
DOCUMENT CONTROL NO.
21-0056
24
______________________________________________________________________________________
REV.
C
1
1
3.5- and 4.5-Digit, Single-Chip
ADCs with LCD Drivers
PDIPN.EPS
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 ____________________ 25
© 2003 Maxim Integrated Products
Printed USA
is a registered trademark of Maxim Integrated Products.
MAX1491/MAX1493/MAX1495
Package Information (continued)
(The package drawing(s) in this data sheet may not reflect the most current specifications. For the latest package outline information
go to www.maxim-ic.com/packages.)